Quinn's reporter girlfriend Christine has now blown the whole Lundy investigation onto the front page, cramping everyone's style and (more importantly) putting Lundy's face on blast for all of Miami -- and Trinity -- to see. Trinity becomes even more familiar with Lundy's face when they both end up location-scouting for the next Trinity murder at the same place, and Trinity engineers a bump-in.
Meanwhile, Rita's taken the kids to a family wedding out of town, giving Dexter the weekend free of his increasingly cumbersome family. Naturally, Dexter takes this opportunity to feed his inner people-carver, this time with one Zoe Kruger, a lady cop who is suspected of offing her husband and child and getting away with it. The irony of this chosen victim isn't lost on Dexter (or Harry), but after pursuing Zoe through several oddly erotic and thematically heavy encounters, Dexter realizes his family IS the most important thing to him. And then he kills Zoe dead.
Deb reaches her tipping point with Lundy, finally realizing resistance is futile and making her move on him (she manages to be regretful about Anton, but only afterwards). Deb and Lundy's time spent staring into each other's eyes is cut short in the hotel parking lot, though, when they're both shot by an unseen assailant. If it's Trinity, he's definitely stepping outside his normal pattern. We end on Deb slipping out of consciousness, while it looks like Lundy may have already checked out.
Previously, Dexter was feeling a tad constricted by his "new" family (who he's largely been around for four seasons now). Like a noose around his neck. Also, Lundy's back in town investigating the Trinity killer, Deb's inching closer and closer to throwing her hot boyfriend overboard to get back with Grandpa, and Quinn's banging a reporter and blabbing to her about the Trinity investigation.
Also, last time we saw Dexter, he was angrily smashing the neighbor's security lights and getting caught by Rita. But as we open the episode, we see Rita saw the incident more as the cry for a few days off that it was. Say what you will about the harpy she's been, but that was a pretty shrewd move. "Time off for bad behavior," is what Dexter's voice-over calls it. Kinda smug for a guy whose wife almost caught him with his Dark Passenger hanging out. He packs the kids into the car (Astor continuing to not win points with me by blatantly disregarding Cody's claim of "shotgun") while Rita good-naturedly bitches about having to "stuff Cousin Marlene into some Spanx on her wedding day. Seeing as Dexter would probably cut Cousin Marlene into six pieces before shoving her into those Spanx, I think Rita's better off taking that one. She's hoping Dexter can use the weekend to unwind, not get to that "boiling point" again. "I hate that you saw me that way," he says. Rita assures him that, as his wife, she wants to know what's going on inside him. "I don't think you do," slam-dunks Dex's VO. She tells him to "go wild" (the VO shows a rare moment of restraint there) and tells him the kids left him a surprise inside, before pulling away.
That surprise? A coffee mug, with the kids' names painted on it, saying "I Love Dad." Dexter is, of course, unmoved by it, because his sociopathology is way bigger than yours. But come on, who doesn't at least let out an "aw" at that? But no, Dexter just starts bopping along to the Cuban music playing in his head and planning his upcoming extracurricular activities.
Cut to: Zoe Kruger, lady cop firing at field targets at the police gun range. Dexter will give you the details: "Eight months ago, officer Kruger's husband and daughter were killed during a home invasion. Zoe was shot in the arm and the foot. She survived, obviously. But there was one person who thought it was Zoe herself who killed her family. The one person who always knows the truth of a crime: the blood guy." Brief flashback to Dexter meeting with said blood guy under some pretense or another (he's writing a book?). At the gun range, Dexter thumbs through Kruger's file, given to him by the blood guy. Back in the lab, Blood Guy points out the blood on the doorjamb left by the assailant (one Darius Rey, a drug dealer Zoe had roughed up the day before) after Kruger supposedly winged him. But Blood Guy said that was the only blood of Rey's at the entire crime scene. Dexter fakes incredulity, so Blood Guy explains even further: He thinks Kruger provoked the day-before confrontation, obtained Rey's blood then, and planted it at the crime scene. Not only does it provide concrete blood evidence, but, as Blood Guys says, it crafts a compelling narrative for the crime -- Rey, out for revenge against Kruger, breaks in and kills her family. Rey was later gunned down in a "supposedly gang-related incident."